Determination of cadmium at ultratrace levels by cold vapour atomic absorption spectrometry

Abstract

Cadmium can be determined by cold vapour atomic absorption spectrometry by utilizing the reaction with tetrahydroborate in aqueous solution. The conditions for the generation of the volatile species were investigated and a method for the determination of cadmium was developed. The characteristic mass of cadmium is 16 pg and the detection limit is 20 pg ml^–1(3s_n–1, peak height mode). The precision of the determination is 1.4% for a cadmium concentration of 3 ng ml^–1. The effects of 30 foreign ions on the determination were investigated and methods for reducing the interferences are suggested. The method was applied to the determination of cadmium in several standard and certified reference materials; the results obtained were in good agreement with the certified values.